This study will evaluate the efficacy of a standardized eight-week home regimen of continuous positive airway pressure (CPAP) therapy for reduction of hypernasality in nonsyndromic unilateral cleft lip and palate subjects between six and twenty-five years old, and of either sex. Seven cleft palate centers will collaborate in the clinical trial. Reference tapes will be compiled, and nasality ratings of subjects' speech samples will be obtained by paired comparisons of subject recordings with standard samples on reference tapes. All speech samples will be rated in this way by the same seven expert listeners, one per clinical center. Reliability, observer variability, and the relation of these calibrated evaluations to conventional scoring based on clinical impressions will be studied. Timing of each speech sample in relation to CPAP therapy will be concealed from listeners. Mean speech ratings from this blinded, controlled procedure will be a primary outcome variable to assess the impact of CPAP therapy. A standard nasalance score will be obtained and measures of momentary velopharyngeal closure, as well as maintenance of closure during conversational speech, will be obtained from brief lateral view videofluoroscopic examinations. These measures will be studied in relation to CPAP therapy and correlated with speech assessment data. Patient satisfaction data will be obtained and related to these outcome variables. Patients in the given age range, without middle ear disease and generally with moderate hypernasality, will be offered the opportunity to participate. A graded, escalating CPAP therapy program will be used, based on the principles of resistance training. Recorded speech samples, nasometry, and videofluoroscopy will be obtained at baseline. Follow-up speech samples and nasometric data will be obtained after four and eight weeks of therapy and, for patients treated within the first eighteen months, at one year following completion of therapy. Post-treatment videofluoroscopy will be obtained, with the other data, at eight weeks. Four months post-therapy, subjects will complete a one-page patient satisfaction questionnaire. The Principal Investigator and other University of Illinois personnel will train investigators in data collection, prepare reference tapes, compile and replicate speech samples for evaluation, and their facilities will serve as the Coordinating and Data Analysis Center. CPAP therapy may provide a low-cost, at-home method for improving quality of life of patients with no demonstrated treatment alternative other than surgery.